I. Field of the Invention
The present invention pertains generally to the field of encryption, and more particularly to methods for authenticating anonymous users that reduce the potential for “middleman” fraud.
II. Background
Computer software is generally distributed over the Internet to end users (i.e., consumers) by distribution agents, or “middlemen.” There are thus three parties involved in the transaction. The first is the provider of software and content (i.e., the author), who derives revenue from providing content to end users and pays a small commission to distribution agents to promote and distribute the software. The second is one of a number of distribution agents who provides the software (which provides a mechanism to view the content, as well as some value independent of the content, such as, e.g., electronic mail functions) to the user. The middleman derives revenue from users who receive content, so it is in his or her interest to distribute the software widely. The third is the user, who gets the software for free in return for viewing the content. The user gets no other remuneration, mainly because the users are anonymous. The users are anonymous because tracking details are generally not kept and the users have not been individually identified. Users might volunteer information when requesting content, but such volunteered information is generally used and discarded rather than being stored or tracked. The parties are hereinafter referred to generally as the provider, the middleman, and the user.
The middleman may use a device known as an Internet “cookie” to obtain demographic information about users when the users connect to the Internet and visit the appropriate website. For example, when a user connects to certain Internet locations, the user's computer connects through the Internet to a host computer operated by the middleman. The host sends a small data file (the cookie) that is saved by the user's computer. As the user and the host communicate, some data is stored in the cookie. When the user disconnects, the cookie remains in his or her computer. Subsequent data about the user's Internet use is stored in the cookie. The next time the user connects to the host, the host reads the cookie for information about the user. The user's information may be compiled by the host operator and sold to Internet marketers.
Because the users are anonymous, the middleman can commit undetectable fraud on the provider simply by passing through more content. This, in turn, can be accomplished either by requesting more content on behalf of a real user, or by creating “fake” users. There are a number of well-known statistical methods for tracking the rate of the content delivery to particular users while keeping the details anonymous. Such statistical methods solve the problem of middlemen committing fraud by requesting more content on behalf of a real user. However, these methods are not directed to the situation in which the middleman commits fraud by creating a significant number of fake users. Thus, there is a need for a method of preventing software distribution agents from impersonating a significant number of nonexistent users to commit fraud.